Current theatres are not suitable for listening to real acoustic ecosystems in that they do not provide a systematic approach for a uniform three-dimensional sound reproduction. As a matter of fact, all traditional theatres, including cinemas, IMAX halls, and planetariums lack speaker systems capable to uniformly cover the spherical (or, at least hemispherical) space surrounding the audience, which is a necessary condition for a full sound reproduction of ecosystems.
The reason why existing theatres do not have this feature is because they were constructed primarily for the viewing of imagery contents which, considered the frontal direction of human sight, offer the spectator a specific frontal view of the subject matter. Such a directional view, in the case of IMAX theatres, is expanded laterally to 180° and in some planetariums the space can be hemispherical and yet, without an isotropic and spherically uniform audio system. The audio systems that exist in theatres today are in fact oriented to offer a preferential directional sound that is consistent with the line of vision. Also, these sound systems are adapted to the movie theatre walls (generally rectangular or square floor plan) and therefore the speakers are not equidistant from the centre of the theatre nor between them. Furthermore, theatres are constructed along sound reproduction standards (e.g. Mono, Stereo, Dolby surround 3.0, 3.1, 4.0, 4.1, 5.0, 5.1, 6.0, 6.1, 7.0, 7.1, THX 10.2 and 12.2, Hamasaki 22.2). Taking into account the said preferential sound orientation to accompany what is seen (frontal sound elements that must combine with the visual elements on the screen and supplemental lateral and rear sound channels with discrete sound content arranged two dimensionally), existing theatres are not satisfactory for a systematic three-dimensional full-periphonic listening experience (equal recontruction of virtual sound sources from all directions—axis X, Y and Z—and correct perspective reconstruction—absolute and relative distances of sound objects). This stands as the optimal and essential condition for a homogeneous reproduction of natural soundscapes as they are found in real ecosystems where sound sources are located all around, above and below the listening position and where distances are very important ecological factors and perceptual cues.
US2007/193123 describes a theatre that consists of a parallelepiped supporting structure, concentric cylindrical benches and steps, a circular band screen that surrounds the benches, speakers and projectors. However, this type of theatre poses problems of acoustics due to the materials used and the form of the supporting structure, as well as for the speaker collocation.
DE 295 07 524 describes a theatre that provides a parallelepiped supporting structure made of sound absorbing materials.